The PULSE ATM/Debit Network is a Discover-owned network which includes large banks, community banks and credit unions.

Its most recent study found that smaller asset debit issuers took a two-cent hit to their debit card interchange on a per transaction basis as a result of the debit interchange cap put into place by the Durbin Amendment.

The organization of retailers and retail associations formed to advocate for lower card interchange took issue with the study on the grounds that it included only 38 smaller asset debit card issuers and because PULSE has not yet released any data about how those issuers were chosen.

“We don't know whether there was bias in their selection or whether they were representative of the segment as a whole,” observed Doug Kantor, counsel to the MPC. Kantor also observed that the study held that the financial institutions surveyed were still making money from their debit programs, even if turned out that debit interchange slipped on a per transaction basis, a suggestion Kantor did not accept.

Kantor pointed out that federal agencies have not found similar results from their studying of the issue and he added that, unlike PULSE, the Federal Reserve can gather data from all banks.